1. Field of the Invention
This invention relates to high temperature gas-cooled nuclear reactors, and more particularly to thermal power cycles for generating useful power from such reactors. The invention is applicable to mobile as well as stationary plants.
2. Description of the Prior Art
Safety considerations relating to the use of high temperature gas-cooled nuclear reactors typically dictate that the power conversion system be either located within a sealed containment vessel, or located outside of the containment and include a heat exchanger within the containment to transfer heat energy from the reactor to the secondary power conversion system. This is particularly true with respect to mobile reactor usage such as in seagoing vessels and contemplated land and air transport systems.
Disposition of the power conversion system, typically including a turbine and compressor, within the containment undesirably increases the containment size, weight and cost over that required for the reactor primary system alone. The power output must then be transferred through the containment such as by a mechanical shaft and a sealed containment penetration or by location of an electrical generator within the containment and the passage of electrical leads through the sealed containment. Containment penetrations through which large quentities of energy are transferred are difficult to design and accordingly costly.
In systems where a heat exchanger is the physical barrier between the primary reactor gas coolant and the secondary working fluid, for an efficient conversion the heat exchanger must operate at temperatures close to the reactor outlet temperature. Such high temperatures at the heat exchanger induce material, design and fabrication concerns such that in many applications either of the typical arrangements are undesirable. For example, in power plants for mobile application it is often necessary to transmit the reactor energy to thermal engines which are remotely located with respect to the reactor and which therefore tend toward the utilization of the heat exchanger arrangement. This arrangement is then complicated by the associated thermal concerns.
It is therefore desirable to provide an arrangement which utilizes the high temperature capabilities of gas-cooled reactors while alleviating these concerns.